1. Field of the Invention
The present invention refers to a method for controlling the manufacturing of tyres for wheels of vehicles.
The present invention refers also to a plant for the manufacturing of tyres for wheels of vehicles.
2. Description of the Related Art
The documents GB2296335 and WO2011/159280 describe methods for determining the structural integrity of a tyre.
Typically a tyre comprises a carcass structure provided with at least a carcass ply having folded end portions opposite to each other. Such end portions are engaged with respective anchoring annular structures, also called “beads”, having an internal diameter substantially corresponding to the so-called “fitting diameter” of the tyre on a respective rim.
The tyre comprises also a belt structure, provided with one or more belt layers, radially overlapping each other and the carcass ply.
Each belt layer can be provided with textile and/or metal reinforcement cords, having a crossed orientation and/or substantially parallel to the circumferential extension direction of the tyre (zero-degree layer).
The tyre further comprises a tread band, made of elastomeric material as the other semi-finished products forming the structure of the tyre itself.
The tyre comprises also respective sidewalls, made of elastomeric material, applied in an axially external position with respect to the side surfaces of the carcass structure, each one of them extending from one of the side edges of the tread band up to the respective anchoring annular structure.
In the tyres of the “tubeless” type, a layer of airtight coating layer, called “liner”, covers the internal surface of the tyre.
In the manufacturing of tyres, the components mentioned above are assembled on one or more building drums, in order to form a green tyre, which is then cured to form the finished tyre.
In the field of the manufacturing of tyres, the need is felt to perform quality controls on the products manufactured, having the twofold purpose of preventing the selling of defective tyres and of regulating progressively the apparatus and the machines used, in order to improve and optimize the performance of each step of the manufacturing process.
Such quality controls can be performed by human operators which, typically at the end of the production line, devote a predetermined time, for example between 30 s and 60 s, to a visual and tactile exam of the tyre. In case, in the light of his/her experience and sensitivity, the operator suspects that the tyre does not fulfil certain qualitative standards, the tyre itself is further tested, by means of appropriate equipment, in order to investigate the presence of possible structural and/or qualitative defects.